All of these books - aside from #9, which was purchased on Ebay in the last few years - were all bought from dealers back in the late 70's and early 1980's. The #3, the copy in the worst condition (I could really use an upgrade!), I remember buying, for $15.00, at the end of the day at the Aqueduct Flea Market in Queens, where my parents had a spot, selling, literally, garbage. But it was good garbage! We'd drive around and collect people's trash, finding some amazing things that folks would throw away. You'd be surprised! I remember once we found about five large glad bags filled with toys. There was even the entire Mego Star Trek Enterprise, and once opened, a bunch of 8" action figures inside. Too bad I didn't keep that! But I digress. At the other end of the spectrum, condition wise, is the #14, the first appearence of the Green Goblin. I'd say my copy is around in 9.0, VF+ condition.
For completions sake for this post, I've reposted the covers to #1 and #9.